It is known to mount a ball bearing assembly between the cylindrical surfaces formed by first and second members through means of a light press fit and a diametral slip fit clearance. For example, the outer race of the bearing assembly can be pressed into a cylindrical bore in a housing so that no relative motion occurs therebetween. A shaft can subsequently be manually inserted into the inner race of the bearing assembly with ease because a diametral slip fit clearance of from about 0.013 mm to 0.10 mm (0.0005" to 0.004") is provided. But this requires an auxiliary device to prevent rotation of the inner race on the shaft.
One such auxiliary restraining device requires that an upstanding lock pin be tightly fitted into a blind bore in the shaft. A recess formed in the inner race is adapted to interlockingly receive the lock pin. While this is a satisfactory and positive way to couple the parts together, it is relatively costly. The dimensions of the blind bore and locking pin must be closely controlled, and then the locking pin must be inserted with a slight interference fit into the bore with specialized tools and with care. Moreover, it takes too much effort to align the parts. Specifically, the assembler cannot simultaneously see the locking pin and the recess in the inner race of the bearing assembly so that it is necessary to radially prealign the components with extreme caution before axially assembling them together.
Resilient elastomeric ring mounts have been used to support the outer race of a ball or roller bearing assembly in a member and to allow considerable self-alignment of the components and the reduction of certain types of vibration. But these soft ring mounts are sometimes difficult to assemble and generally allow excessive radial movement and lack the degree of positive positioning that is so desirable in heavily loaded rotating mechanisms such as a vehicle transmission. In addition, many of these ring mounts are relatively expensive and often require considerable space in an area where space is at a premium.
NTN Toyo Bearing Co. Ltd. offers an expansion compensating bearing with a pair of flat polyamide bands mounted in corresponding parallel grooves formed in the periphery of the outer race of a ball bearing assembly. The coefficient of thermal expansion of the bands is relatively high so that the steel ball bearing can operate under the same interference fit conditions with respect to an aluminum housing bore at various operating temperatures. Unfortunately, the grooves in the race can weaken the structural integrity of the bearing and since it is non-standard the costs to use it are higher than desired.
Thus, what is needed is a low-cost, standard ball or roller bearing assembly race retention device for the race that has a diametral slip fit clearance without providing a recess in the race that would otherwise add cost or possibly serve to weaken the structural integrity thereof. Further, the retention device and method that prevents rotation of the race should not require radial prealignment of the parts and should be capable of axial assembly with minimal manual effort. Optimally, the subject retention device should minimize the problem of fretting between the race and associated member, and also be capable of positive operation over a considerable period of time in a power train, transmission or the like of the type that would experience an operating temperature range above about 40.degree. C. (104.degree. F.) and up to about 120.degree. C. (250.degree. F.) in the presence of oil or other petroleum-based lubricating fluid.